Major League Baseball, MLB Players Association plan to hold multiple bargaining sessions next week, sources say

Major League Baseball and the MLB Players Association intend to hold multiple bargaining sessions -- perhaps every day -- as early as Monday, sources told ESPN's Jeff Passan.

While exact plans are not finalized, multiple owners and players expect to fly in for sessions leading up to MLB's stated Feb. 28 deadline.

Meanwhile, a bargaining session between MLB and the players' union lasted just 15 minutes Thursday and produced little progress toward a new collective bargaining agreement, sources familiar with the situation told ESPN.

The union offered tweaks to its arbitration demands while asking MLB for more money in a pre-arbitration bonus pool, according to sources.

A three-man MLB delegation led by deputy commissioner Dan Halem arrived shortly before 1 p.m. ET for just the sixth negotiating session on core economics since the work stoppage began in December. The sides met on the 78th day of the lockout and one day after spring training workouts were scheduled to commence, but sources told ESPN that neither side felt there was much progress in the negotiations.

Players expressed anger about MLB's lack of movement on the competitive balance tax, while the league expressed frustration about the union's lack of counteroffer on the game's core economic issues, according to sources.

MLB is expecting a proposal Friday on several non-core economic issues. Halem and head union negotiator Bruce Meyer held a 20-minute side conversation Thursday after the negotiating session, a one-on-one meeting that was described as unusually candid.

In its new proposal, the union asked for 80% of players with two years of service time to enter the arbitration system, down from a previous request of 100%. Currently, 22% of second-year players -- known as Super 2s -- enter arbitration.

Under the new offer, 20% of second-year players would remain in pre-arbitration, but the union also increased its request to $115 million in the pre-arbitration bonus pool for the top 150 players. MLB is offering $15 million to the top 30 players according to WAR.

The union previously had asked for $100 million in the pool but also wanted all players with two years of service time to reach arbitration.

Arbitration is just one major issue that needs resolving before a deal can be reached.

There was no discussion Thursday of key issues such as luxury tax thresholds and rates, the minimum salary, the union's proposal to decrease revenue sharing and the players' allegations of service time manipulation. The sides remain far apart in all those areas and also differ on the postseason: Owners want to expand the playoffs from 10 teams to 14, while players are offering 12.

The owners locked out the players on Dec. 2 after the last collective bargaining agreement expired. With spring games scheduled to begin Feb. 26, there is fleeting hope that any games will be played in Arizona or Florida this month. Spring camps need to open in early March for the regular season to start on time.

The union told MLB it was prepared to meet every day next week.

ESPN's Joon Lee and The Associated Press contributed to this report.